JP2004126692A5

JP2004126692A5 -

Info

Publication number: JP2004126692A5
Application number: JP2002286326A
Authority: JP
Filing date: 2002-09-30
Publication date: 2005-04-07
Anticipated expiration: 2022-09-30

Description

【００３８】
【課題を解決するための手段】
上記目的を達成するため、本発明の第１の観点は、描画対象の表面上の一点に入射する光が物体表面で反射される割合を表す関数であるＢＲＤＦモデルに基づいて反射率を求める画像処理装置であって、光源方向ベクトルと視点方向ベクトルと法線方向ベクトルからなるベクトルと、ＢＲＤＦモデルの特性を決める行列を含む２次形式の行列表現で計算されるＢＲＤＦモデルに基づいて上記反射率を計算する演算手段を有する。 [0038]
[Means for solving problems]
In order to achieve the above object, the first aspect of the present invention is an image for obtaining a reflectance based on a BRDF model, which is a function representing the ratio of light incident on a point on the surface of a drawing target reflected on the surface of an object. The reflectance is based on the BRDF model, which is a processing device and is calculated by a quadratic matrix representation including a vector consisting of a light source direction vector, a viewpoint direction vector, and a normal direction vector, and a matrix that determines the characteristics of the BRDF model. Has an arithmetic means for calculating.

本発明の第２の観点は、描画対象の表面上の一点に入射する光が物体表面で反射される割合を表す関数であるＢＲＤＦモデルに基づいて反射率を求める画像処理方法であって、光源方向ベクトルと視点方向ベクトルと法線方向ベクトルからなるベクトルと、ＢＲＤＦモデルの特性を決める行列を含む２次形式の行列表現で計算されるＢＲＤＦモデルに基づいて上記反射率を計算する。 A second aspect of the present invention is an image processing method for obtaining a reflectance based on a BRDF model, which is a function representing the ratio of light incident on a point on the surface of a drawing target reflected on the surface of an object, and is a light source. The reflectance is calculated based on the BRDF model calculated by a quadratic matrix representation including a vector consisting of a direction vector, a viewpoint direction vector, and a normal direction vector, and a matrix that determines the characteristics of the BRDF model.

また、本発明では、上記光源方向と視点方向と法線方向からなるベクトルは、所定の線形変換を用いて次数を退化させたものである。 Further, in the present invention, the vector consisting of the light source direction, the viewpoint direction, and the normal direction is a degenerate order using a predetermined linear transformation.

好適には、上記２次形式の行列表現で計算されるＢＲＤＦモデルの特性を決める行列を小行列に分割して、分割した小行列の２次形式からなる多項式を用いて評価演算する。 Preferably, the matrix that determines the characteristics of the BRDF model calculated by the above - mentioned quadratic form matrix representation is divided into submatrixes, and the evaluation operation is performed using a polynomial composed of the quadratic form of the divided minors.

また、好適には、上記２次形式を行列とベクトルの乗算後、ベクトル同士の乗算をする手順で計算する。 Further, preferably, the above quadratic form is calculated by a procedure of multiplying a matrix and a vector and then multiplying the vectors.

Claims

An image processing apparatus for obtaining a reflectance based on a BRDF model, which is a function representing a rate at which light incident on one point on a surface to be drawn is reflected on an object surface,
Arithmetic means for calculating the reflectance based on a BRDF model calculated by a quadratic form matrix representation including a vector comprising a light source direction vector, a view direction vector and a normal direction vector, and a matrix which determines characteristics of the BRDF model Image processing apparatus having.

The image processing apparatus according to claim 1, wherein the vector including the light source direction, the viewpoint direction, and the normal direction is any one of a three-dimensional vector representing a direction, a quaternion, and a polar coordinate.

2. The image processing apparatus according to claim 1, wherein the vector composed of the light source direction, the viewpoint direction, and the normal direction is one in which the order is degraded using a predetermined linear transformation.

2. The image processing apparatus according to claim 1, wherein the vector composed of the light source direction, the viewpoint direction and the normal direction is a vector obtained by converting these vectors by arbitrary elementary operations, table reference, or a combination thereof.

The calculating means, the matrix that determines the characteristics of the B RDF model that will be calculated by the matrix representation of the quadratic form is divided into submatrices, evaluates calculation using the polynomial comprising a quadratic form of divided sub-matrices according An image processing apparatus according to claim 1.

2. The image processing apparatus according to claim 1, wherein said arithmetic means is calculated in the procedure of multiplying vectors after multiplication of matrices and vectors in said quadratic form.

The image processing apparatus according to claim 1, wherein the evaluation result of one or more of the BRDF models is synthesized by selectively using addition and subtraction, multiplication, division, accumulation, and quadratic forms.

The operation means has two operation modes of a matrix operation expression consisting of two different vectors and a sum of a quadratic form matrix including a triangular matrix and a vector multiplication, and has a compound operation unit for calculating the BRDF model. An image processing apparatus according to claim 1.

The arithmetic means is obtained by solving a matrix which determines the characteristics of the BRDF model by solving an equation comprising a plurality of polynomials obtained by substituting a plurality of BRDF raw data given in advance into the BRDF model. Image processing device.

From the correspondence obtained by assuming that the above-mentioned calculation means has the same distribution as the reflectance distribution of the specular light corresponding to the direction of the half vector, the reflectance distribution of the diffuse (diffuse) corresponding to the light source direction is poly The image processing apparatus according to claim 1, wherein a matrix that determines the characteristics of the BRDF model is created from parameters of a nominal texture map.

An image processing method for obtaining a reflectance based on a BRDF model, which is a function representing a rate at which light incident on one point on a surface to be drawn is reflected on an object surface,
An image processing method for calculating the reflectance based on a BRDF model calculated by a quadratic form matrix representation including a vector including a light source direction vector, a view direction vector and a normal direction vector, and a matrix that determines characteristics of the BRDF model .